Point-to-point measurements using a handheld device

Abstract

A method for performing point-to-point measurements includes (i) determining a distance to a first point and obtaining an image at a first pose, and (ii) determining a distance to a second point and obtaining an image at a second pose. The images have an overlapping portion. A change in pose between the first pose and the second pose is determined using observed changes between common features in the overlapping portion of the images and a scale associated with the images. A distance between the first point and the second point is determined based on the first distance, the second distance, and the change in pose between the first pose and the second pose.

What is claimed is: 
     
       1. A method for performing point-to-point measurements, the method comprising:
 at a first pose:
 determining a first distance to a first point using a distance measurement device; and 
 obtaining a first image using an imaging device, wherein:
 the first distance is determined concurrently with obtaining the first image such that measurement time is reduced compared to sequentially taking a measurement and a picture; and 
 the first image does not include the first point; 
 
 
 at a second pose:
 determining a second distance to a second point using the distance measurement device, where the second point is different from the first point; and 
 obtaining a second image using the imaging device, wherein:
 the first image and the second image having an overlapping portion; 
 the second distance is determined concurrently with obtaining the second image; and 
 the second image does not include the second point; 
 
 
 determining a change in pose of the imaging device between the first pose and the second pose using:
 observed changes between common features in the overlapping portion of the first image and the second image; and 
 a scale associated with the first image and the second image to determine units of distance for translation between the first pose and the second pose; and 
 
 determining a distance between the first point and the second point based on the first distance, the second distance, and the change in pose of the imaging device between the first pose and the second pose. 
 
     
     
       2. The method of  claim 1  wherein at least one of the first image or the second image includes an object of known size that is used to resolve the scale. 
     
     
       3. The method of  claim 1  further comprising:
 determining a distance to a point that is captured in at least one of the first image or the second image; and 
 resolving the scale using the distance to the point. 
 
     
     
       4. The method of  claim 1  further comprising:
 projecting a known pattern of light onto an object that is captured in at least one of the first image or the second image; 
 determining a distance to the object using the known pattern of light in at least one of the first image or the second image; and 
 resolving the scale using the distance to the object. 
 
     
     
       5. The method of  claim 1  wherein the imaging device is a depth camera, the method further comprising:
 determining a distance to an object that is captured in at least one of the first image or the second image using the depth camera; and 
 resolving the scale using the distance to the object. 
 
     
     
       6. The method of  claim 1  further comprising:
 determining a distance to an object that is captured in at least one of the first image or the second image using a location of focused radiation on the object and a known relationship between a field of view of the imaging device and the location of the focused radiation in the first image or the second image; and 
 resolving the scale using the distance to the object. 
 
     
     
       7. The method of  claim 1  further comprising:
 from a third pose: 
 determining a third distance to a third point using the distance measurement device, the third point located on a line extending between the first point and the second point; and 
 obtaining a third image using the imaging device, where the first image, the second image, and the third image have overlapping portions; 
 resolving the scale using observed changes between common features in the overlapping portions of the images and the first distance, the second distance, and the third distance. 
 
     
     
       8. The method of  claim 1  wherein a location of the first pose is different from a location of the second pose. 
     
     
       9. An apparatus for performing point-to-point measurements, comprising:
 a distance measurement device configured to acquire distance information; 
 an imaging device configured to acquire image information concurrently with the distance measurement device acquiring distance information such that measurement time is reduced compared to sequentially taking a measurement and a picture; and 
 a processor configured to:
 receive the distance information, the distance information including a first distance to a first point obtained at a first pose and a second distance to a second point obtained at a second pose; 
 receive the image information, the image information including a first image obtained at the first pose and a second image obtained at the second pose, wherein:
 the first image and the second image have an overlapping portion; 
 the first distance is determined concurrently with obtaining the first image; 
 the first image does not include the first point; 
 the second distance is determined concurrently with obtaining the second image; and 
 the second image does not include the second point; 
 
 determine a change in pose of the imaging device between the first pose and the second pose using:
 observed changes between common features in the overlapping portion of the first image and the second image; and 
 a scale associated with the first image and the second image to determine units of distance for translation between the first pose and the second pose; and 
 
 determine a distance between the first point and the second point based on the first distance, the second distance, and the change in pose of the imaging device between the first pose and the second pose. 
 
 
     
     
       10. The apparatus of  claim 9  wherein the distance measurement device is an electronic distance meter (EDM). 
     
     
       11. The apparatus of  claim 9  wherein the imaging device is a digital camera. 
     
     
       12. The apparatus of  claim 9  wherein a location of the first pose is different from a location of the second pose. 
     
     
       13. The apparatus of  claim 9  wherein:
 the distance measurement device is further configured to determine a distance to a point that is captured in at least one of the first image or the second image; and 
 the processor is configured to resolve scale using the distance to the point that is captured in at least one of the first image or the second image. 
 
     
     
       14. The apparatus of  claim 9  wherein:
 the image information further includes a third image obtained at a third pose; and 
 the processor is further configured to determine a change in pose between the second pose and the third pose.